75-15=60 27-18=9 9-9=0 60+0=60 60+26=86
1. (620-129×3)-128:4-2=205.
1) 129×3=387;
2) 620-387=239;
3) 128:4=32;
4)239-32=207;
5)207-2=205.
2. 620-(129×3-128:4)-2=263.
1) 129×3=387;
2) 128:4=32;
3) 387-32= 355;
4) 620 - 355= 265;
5) 265 - 2 = 263.
3. 620-129×3-128:(4-2)=169.
1) 129×3=387;
2) 4-2=2;
3)128:2=64;
4) 620-387=233;
5) 233-64=169.
V(t)=S'(t)=(t^3-2t^2+t)'=2t^2-4t
a(t)=S''(t)=v'(t)=(2t^2-4t)'=4t-4
8=4t-4
t=12/4=3 сек.